Commons In A Box is not a fork of BuddyPress. It utilizes BuddyPress as well as other vetted BuddyPress plugins together to form an easy package to work from. The rationale is you shouldn’t have to go and find which plugins work and don’t work. CBOX also packages a nice theme to work with that is easily customizable.

Check out the CBOX website for more info. Also feel free to register and ask questions over there.